A Microsoft Corp. executive on Tuesday addressed the recent Skype outage by comparing VOIP (voice over Internet Protocol) to early automobiles in a horse-drawn world.

A buggy salesman would tell you not to buy a car because it could break down, but no one’s taking horse-drawn buggies to work anymore, said Gurdeep Singh Pall, corporate vice president of Microsoft’s Unified Communications Group.

Many Skype Ltd. customers were unable to log in for about 36 hours last week, and on Monday the peer-to-peer Internet voice provider blamed the impact of people going back on to the service after installing Microsoft software updates. Pall said the industry as a whole has work to do.

“I’m not saying there are no problems, I’m saying … we need to fix those problems and deal with them,” Pall said in a keynote address at the VoiceCon conference in San Francisco.

However, he warned attendees to the VOIP show not to use Skype, owned by eBay Inc., in their enterprises. The call quality is fine, but a salesman who has built up customer contacts using his Skype ID could take that ID with him when he left for a competitor, Pall said.

Pall also sought to reassure people about Microsoft’s unified communications partnership with Nortel Networks Corp., announced with fanfare last year, in which the two companies are doing joint development. On Monday, Microsoft announced it will work with Nortel rival Cisco Systems Inc. to make sure its products work together with Cisco’s.

“I’m actually very excited about the Nortel thing,” Pall said. Without giving specifics, he said both companies have had more success than they expected from the partnership, including customers being persuaded to go with Nortel because of its tie to Microsoft. But the deal isn’t exclusive, and Microsoft is open to relationships with other vendors, he said.

In the keynote, Pall announced that Microsoft is licensing its RT Audio Codec to Intel Corp., Texas Instruments Inc. and other vendors. RT Audio Codec adapts so it can digitize voice calls with good quality over both slow and fast network connections, he said.

Pall also announced the Office Communications Server 2007 Quality of Experience Monitoring Server, which will let IT managers watch IP call quality in real time and create reports using applications such as Excel and Access, he said.